Gingrich also leads Romney 43 percent to 20 percent in South Carolina, and 48 percent to 25 percent in Florida, the poll found.

Earlier, in response to a question from an Iowan in the audience of 150 to 200 at the Kum & Go convenience store chain headquarters, Christie said he doubts he will be on the ticket as a vice presidential candidate.

“I wouldn’t bet on Romney-Christie,” he said. “I wouldn’t lay any money on that. But one never knows. We can live and hope.”